Timer apparatus



1386- 1953 D. F. ILLIAN ETAL TIMER APPARATUS 3 Sheets-Sheet 1 Filed Oct. 14, 1952 INVENTORS Douglas 1? Ill/an Norman I Terp EmSQ Dec. 22, 1953 D. F. lLLlAN ETAL TIMER APPARATUS 3-Sheets-Sheet 2 Filed Oct. 14, 1952 INVENTORS Douglas E I l/ian Norman I Terp E: Q i I I Anys D6622, 1953 D. F. lLLlAN ETAL 2,663,786

TIMER APPARATUS Filed Oct. 14, 1952 3 Sheets-Sheet 3 Fig. 5

INVENTORS Doug/as 1-'. Ill/an BY Norman I Terp M, 0% M Patented Dec. 22, 1953 STATES PATENT OFFICE TIMER. APPARATUS Douglaslllian, Oak Park, "and Norman T. Tel-p, ilhicago, Ill., assignors to General Electric "Company, 'a' corporation of New York implication October 14, 1952,.Seria'l No. 314,674

22 Claims.

The pr'es'entinvention relates to timer apparatus, and more particularly 'to clock-controlled switching equipm'e'ritfor selectively governing the electric heating s stem of an oven, or the'like.

An electric range ordinarily comprises an oven provided with timer ap aratus for selectively closing and openingthe heating circuit thereof respectively at set start and stop vclock times so that an automatic cooking Operation may be carried outin the oven under the control of the timer apparatus "after setting thereof. This timer apparatus conventionally comprises a manually operable master control lever that is selectively operablel'int'o"on; tilt and manual positions, as Well-as atleas't one manually operable knob for seiecfive1ysetfing the start clock time'and the stop clockit'ime. Further, the heating circuit'nor'rnally comprisesa manually operable s'elector switch-havinglbroil}"off; manual bake 'an'dtime bake""pos'itions', as well as a manually setta'ble' oven temperature regulator. Now all of these devices must be properly controlled an'd'set in" order 'to condition the heating circuit for an automatic cook'in'groperation in the oven; and further, the operator must remember to disable the timer apparatus after an automatic cooking ope'ration'inorder to restore the heating circuit to'manual control. Specifically, after an automatic cooking operation, the operator "must operate the master-controlTleverof the'timer apparatus from it's' o'if .positio'n back into its manual position .in order that the selector switch in its"manual bake position. may. govern the heating circuit on amanualbasis, since the timer apparatus incorporates switch contacts that are arranged in series circuit relationship with the "manually operable selector switch. Needless to say; all of this manip'ulation of theknobs and'leversiin orde'rlto shift'btween manual control and automatic control of the-cooking opera- 1 sociated switching mechanism into its respective and corresponding controlppositions, regardless of the set or unset position of the associated timer mechanism, whereby the control position of the member overrides the control position of the timer mechanism with respect to the actualicontrol of the switching mechanism.

Another object of the invention is to provide in combination manual-controlled and clockcontrolled switching apparatus, an improved and simple arrangement governed by initial manual control of the switching mechanism for placing subsequent automatic control thereof under the timer'mechanism.

Another object of'lth'e invention is 'to provide timer apparatus of improved construction and arrangement so that it may serve both as an attractive kitchen clock and as a simple controller for a selector switch that is also manually operable"and'that'is incorporated in an associated heating circuit.

A further object of the invention is to provide timer apparatus incorporating an improved arrangement of the start dial and the stop dial thereof, so as 'to accommodate ready setting of corresponding start andistop clock times and cor- .responding direct indicationsof the set start and stop clock times with reference to the normal clock time indi'cia thereof.

A further objector the invention is to provide timer apparatus incorporating an improved ar rangement'including a single manually operable control member for selectively setting sequentially thestop dial and "the start dial incorporated therein so that thetimer'maybe used either only'for stopping at a set stop clock time a manually started cooking operatiomor both'for starting a'cooking operation at a set start clock time and later for .stoppingthe cooking operation at a set stop clock time.

Further features of the invention pertain 'to the-particular arrangement'of the elements of'the timer apparatus andthe heating system, whereby the above outlined'andadditional operating features thereo'f are'attained.

The invention, both as toits organization and method of operation, together with further objects an'dadvantages thereof, will best be understood by reference "to the following specifications taken in connection with the accompanying drawings, in which *Figure 1 is a fragmentary front elevationalview of-theupper portion or an electric range provided with a heating system present invention;

Fig. 2 is an enlarged front elevational view of the timer apparatus that is supported in the backsplash of the electric range;

Fig. 3 is a diagrammatic illustration of the electric heating system of the oven incorporated in the electric range;

Fig. 4 is a further enlarged fragmentary front elevational view, partly in section, of the timer apparatus shown in Fig. 2; and

Fig. 5 is a further enlarged fragmentary horizontal sectional view of the timer apparatus, taken in the direction of the arrows, along the offset line 5-5 in Fig. 4.

Referring now to Fig. 1 of the drawings, the electric range I0 there illustrated incorporates a heating system including timer apparatus l l and embodies the features of the present invention. More specifically, the range ill includes an upstanding body !2 provided with a substantially horizontal cooking top l3 supporting the different i surface heating units or hot plates i4, i5, i6 and H arranged in spaced-apart relation on the lefthand side thereof. The body l2 houses an oven l8 in the right-hand portion thereof and a storage compartment l9 in the left-hand portion thereof. the oven l8 and the compartment is being accessible through respective front openings pro vided with respective front doors 2G and ii. The cooking top 13 carries an upstanding backsplash 22 adjacent to the rear thereof that carries four manually operable selector switches 23, 24, 25 and 26 respectively corresponding to the surface heating units l4, l5, l6 and H, all arranged in a horizontal row on the lower righthand portion thereof. Also, the backsplash 22 carries an oven regulator 21 and an alarm timer 28 on the upper right-hand portion thereof, the timer apparatus it being carried on the upper left-hand portion of the backsplash 22.

As best shown in Figs. 2 and 5, the timer apparatus ll comprises a casing or housing 28 that may be placed directly in a corresponding opening provided in the left-hand upper portion of the backsplash 22 and secured in place by any suitable arrangement, not shown. Specifically, the

casing 29 includes a substantially flat front wall 30 disposed substantially flush with the front of the backsplash 22 and a removable rear wall 3| readily accessible from the rear of the back splash 22; and the casing 29 houses a manually operable oven selector switch 32 of the rotary snap type and provided with a rotatable operating shaft 33 projecting forwardly through a cooperating hole formed in the front wall 39 and carrying on the extreme outer end thereof an operating knob 34 that cooperates with suitable indicia provided in arcuate array on the adjacent portion of the front wall 39. Specifically, as illustrated in Figs. 2 and 3, the oven selector switch 32 comprises a normal off position, an

adjacent normal bake position and an adjacent timer bake position, as well as a broil position disposed adjacent to the normal bake position and a timer off position disposed adjacent to the timer bake position; the normal bake and the broil positions being disposed .on the left-hand side of the normal 01f position, and the timer bake and the timer off positions being disposed on the right-hand side of the normal off position.

The oven selector switch 32 may be of any conventional construction and comprises, as illustrated in Fig. 3, two insulating cams 35 and 33 carried on the inner end of the operating shaft 33 and provided with respectively cooperating pairs of switch springs S31, S38 and S39, S40. Also, as illustrated in Fig. 3, the oven I8 is provided with upper and lower heating elements 4| and #32 of any suitable type and an associated three-wire Edison source of 230 volts, single phase, the source of current supply including a grounded neutral conductor &3 and two ungrounded outside conductors M and 45. The neutral conductor 43 and the outside conductor 44 are respectively connected to the movable springs of the sets of switch springs S31 and S38; while the outside conductor 45 is commonly connected to the movable springs of the sets of switch springs S39 and S40. The stationary springs of the sets of switch springs S31 and S38 are respectively connected to two conductors 66 and t1; the stationary spring of the set of switch springs S39 is also connected to the conductor t8; and the stationary spring of the set of switch springs S46 is connected to a conductor 48. The oven regulator 27 comprises a manually settable temperature dial es, as well as a control switch 56 that includes three bridging members 5!, 52 and 53. The bridging member 55 is provided with an associated pair of contacts, one of the contacts terminating the conductor 4t and the other of the contactsterminating one terminal of the heating element dl The bridging member 52 is provided with an associated pair of contacts, one of the contacts terminating the conductor 33 and the other of the contacts terminating one terminal of the heating element 42. The bridging member 53 is provided with an associated pair of contacts, one of the contacts terminating the conductor All and the other of the contacts commonly terminating the other terminals of the heating elements ll and -12. Finally, the oven regulator 21 comprises a temperature responsive bulb 55 that is operatively associated with the oven l3 and that is connected to the housing thereof by an associated capillary tube 55. It will be understood that when the oven 53 is at a temperature below that set by the temperature dial 59, the oven regulator 21 is operated to actuate the control switch 50 into its closed position; and on the other hand, when the oven 13 is at the temperature set by the temperature dial 29, the oven regulator 2'! is operated to actuate the control switch 5.0 into its open position. Thus in the operation of the oven E8, the oven regulator 27 selectively actuates the control switch 50 to maintain the temperature in the oven it to that set by the temperature dial =39, in a conventional manner.

Continuing now with the operation of the oven selector switch assume that the control switch 5% occupies its closed position. When the oven selector switch 32 occupies either its normal off or its timer oif position, the sets of switch springs 33?, S38, S39 and S it occupy their open positions; whereby all of the circuits to the heating elements ii and 22 are interrupted. When the oven selector switch occupies either tis normal bake or its timer bake position, the sets of switch springs Sfil, S38, and sec occupy their closed positions while the set of switch springs S55! occupies its open position; whereby the upper heating unit M is energized across the volts supplied between the neutral conductor 43 and the outside conductor at, and the lower heating unit 6. 2 is energized across the 230 volts supplied between the outside conductors it and 45. When the oven selector switch 32 occupies its broil position,

the s of sw t h springs 1 and sim e their open positions and the sets or "switch springs S38 and S39 occupy their closed posi tions; whereby the upper heating unit 4 lis eh' er'gized across the 230 volts supplied between the outside conductors 44 and 4 5, and the lower heating unit 42 is deenergized; k I

Finally, the insulating cams' 35 and 36 are provided with coordinately arranged shallow and deep notches therein that maintain the several positions of the oven selector switch 32 and respectively bring about opening and closing of the associated sets of switch springs S31, etc, in a conventional manner; I N

Further considering the construction of the timer apparatus ll, and referring particularly to Fig. 5, it is noted that also arranged inth'e casing 29 are front and back supporting plates 55 and 57% secured together in spaced-apart relation, the plate 5% being retained in place by an arrangement including an angle bracket 58 re? movably secured thereto and carried by the wall of the casing 29. As illustrated; the selector switch also includes an enclosing housing fia that may be formed of insulating material and suitably secured to the rear of the plate 56. Also, an electric motor 60 of the synchronous type, and preferably a Telechron unit, is arranged between the rear wall 31 and the plate 5'! and suitably supported upon the plate 51, the motor 68 including the usual elementgas well as a gear box El and a forwardly projecting operating shaft 82 extending through an associated hole provided in the plate 51'. In the arrangement, the operating shaft 62 is rotated on a time basis at one revolution per hour and comprises the drive motor for the clock mechanism. V v 7 Also, the clock mechanism comprises a forwardly projecting bushing 63 secured ina cooperating hole formed in the plate 5 6 and supporting a minute arbor of shaft 64 interiorly thereof and an hour arbor or sleeVeB-S exteriorly thereof, the center line of the minute arbor 64 being aligned with respect to the center line of the operating shaft 52. The front end of the operating shaft 82 and the rear end of the minute arbor 64 are connected together by a friction clutch 66, including cooperating frictionally engaged clutch plates 61 and 68 respectively carried by the operating shaft 62 and by the minute arbor 55; whereby rotation of the operating shaft 32 normally rotates the minute arbor but the minute arbor 64 is rotatable with respect to the operating shaft 62. The extreme front end of the minute arbor 6'4 carries a manually operable knob 69 disposed somewhat forwardly with respect to the front wall 30 and accommodating ready rotation of the minute arbor 5d. n v As illustrated in Figs. 2, 4 and 5, the front Wall as of the casing 29 is provided with an annular depression i9 defining a flange H terminating in an annular groove i2 surrounding a circular opening '53 formed therethrough, the elements ill, H, l2 and 13 being disposed concentric with the minute arbor 84 and spaced well radially therefrom. An outwardly dished disk like crystal l4, formed of glass, or the like, is ar ranged in covering relation with the circular opening it, the rim of the crystal 14 being disposed in the annular groove 12, and the central portion of the crystal 14 having a hole l5 formed therein through which the front end of I the minute arbor 64 projects sothat the knob 69 is disposed well forwardly of the crystal H. The

crystal T4 is retained'inplace by an associated annular ring lfi having a rearwardly directed outer flange l1 frictionally engaging the edge of the annular depression 10; whereby the ring 16 c'onstitutes a bezel bearing appropriate time indicia on the front face thereof.

The minute arbor'64 carries a rnihute hand 18 disposed rearwardly of the crystal 7'4; and the outer end of the hour arbor '65 carries an hour hand 19 disposed rearwardly of the minute hand 18, the hands18 and being disposed Within the ring 18 and-cooperating with the time indicia borne thereby in the usual clock relationship. The rear end of the minute arbor 6'4 has a pinion secured thereto behind the plate 53; which pinion 8!! meshes with a'gear Bl carried by a shaft 82 extending between theplates 56 and 51-. The front end of the shaft 82 carries a pinion 83 that meshes with a gear 8 4 carried adjacent to the rear end of the hour arbor 65". In the arrangement, the pinion 8t and the gear 8| bring about a 211 speed reduction between the minute arbor B4 and the shaft 82; while the pinion 83 and the gear 84 bring about a 6 1 speed reduction between the shaft 82 and the hour arbor 65. Accordingly, it will be appreciated that clockwise rotation of the operating shaft 62 at one revolution per hour brings about clockwise rotation of the minute arbor 64 at one revolution per hour through the friction clutch 69; whereas clockwise rotation of the minute arbor 64 at one revolution per hour brings about clockwise rotation of the hour arbor 65 at revolution per hour through the gears ea, 8|, as and 84. Hence the minute hand 13 rotates in the clockwise direc'tion at one revolution per hour and the hour hand 19 rotates in the clockwise direction at 1 revolution per hour; whereby the hands 18 and [9 cooperating with the ring 76 provide the usual clock relationship.

Further, the timer apparatus H comprises a front stop dial or disk 85, a rear start dial or disk 86 and a rear start gear 81 rotatably mounted upon the hour arbor 65'. More particularly, the central portion of the start disk 86 is rearwardly dished and directly engages the central portion of the start gearfll disposed 'rearwardly thereof, the start disk 86 and the start gear 87 being rigidly secured together by a plurality of rivets 88. The stop disk is disposed forwardly of the start disk 86, the spacing therebetween being maintained by an annular collar 89 disposed therebetween and surrounding the hour arbor 65, the stop disk8'5 being retained inplace by an annular collar 9'0 disposed on the front side thereof and surrounding the hour arbor 65, and the start gear 87 being retained in place by an annular shoulder 9| formed on the hour arbor 65. In the arrangement, the collar 90 may be rigidly secured to the hour arbor 6'5 and-the collar 89 may be loosely carried thereby. In any case, the stop disk 85 is readily rotatable with respect to the hour arbor 55 independently thereof; and the start disk 86 and the start gear 81 rigidly secured together are readily rotatable together with respect to the hour 'arbo'r '6'5 and independently thereof. Finally, the hour arbor 65 carries an annular fixture 92 disposed rearwardly of the start gear 8! and having a radially projecting arm 93 that cooperates with a rearwardly directed lug or tab 94 bent out of the start gear 87 and cooperating therewith. Also, the front side of the start disk 85 carries a substantially L-shaped lug or tab 95 that projects forwardly into an arcuate slot 96 formed in-the stop disk '85 and extending throughan angle of'18 0 one end of the 'arcuate slot 96 having an offsetrecess 91 formed therein.

and adapted to receive the lug 85.

In view of the foregoing, it will be understood that the start disk 86 has a normal position wherein it is disposed coincident with the hour arbor 65, the arm 93 engaging the lug 94 at this time and rotating the start disk 86 (also the start gear 8'!) with the hour arbor 65. Similarly, the stop disk 8:: has a normal position wherein it is disposed coincident with the start disk 88, the lug 95 engaging the adjacent end of the slot 95 at this time and rotating the stop disk 85 with the start disk 35. Further, the start disk 86 has a variable set position disposed ahead of the hour arbor 65, wherein the start disk 85 is not rotated with the hour arbor 65 when it occupies its set position. Similarly, the stop disk 85 has a variable set position disposed ahead of the start disk 85, wherein the stop disk 85 is not rotated with the start disk 86 when it occupies its set position. For the purpose of correlating the set position of the stop disk 85 with respect to the time ring it, an index pointer 98 (preferably red) is provided on the stop disk 85 adjacent to one end of the slot at formed therethrough; and for the purpose of correlating the set position of the start disk as with respect to the stop disk 85 and to the time ring it, an inner arcuate band as (preferably red) and an adjacent outer arcuate scale Hill are provided on the start disk 86 and cooperate with the legend time to bake provided on the stop disk 85 adjacent to the index pointer 98, the red band 99 and the scale it!) being visible through the slot 95 provided in the stop disk efi'when the start disk 86 occupies its set position. More particularly the exposed ends of the red band 33 and the scale Wt cooperating with the adjacent end of the slot 96 indicate the baking time interval between the set stop clock time and the set start clock time; the cooperation between the index pointer 98 and the time ring it indicates the set stop clock time; and the cooperation between the ends of the red band 99 and the scale use and the time ring 76 indicate the set start clock time.

For the purpose of selectively setting the stop disk 85 and the start disk 86, an arrangement is provided that includes a manually operable setting control knob IEH provided on the extreme outer end of a rearwardly projecting shaft I92 mounted for rotation in the plates 56 and 57, the shaft I92 projecting through a notch H33 formed in the right-hand side of the time ring TE and through an associated hole its provided in the front wall 30 adjacent to the depression it, as shown in Fig. 5. The intermediate portion of the shaft Hi2 carries a gear lot that meshes with the teeth provided on the periphery of the start gear 81. Thus, it will be understood that by rotation of the setting knob It! in either direction, the start gear 81 is rotated in the opposite direction by virtue of the mesh between the teeth provided on the gears 8! and IE5. In order to set the stop disk 85 out of its normal position, the setting knob I! is rotated in the counterclockwise direction efiecting rotation of the start gear 87 in the clockwise direction; whereby the start disk 8'! is rotated out of its normal position in coincidence with the hour arbor 65. As the start disk 86 is thus rotated in the clockwise direction, the lug 95 engages the adjacent end of the slot 96 provided in the stop disk 85 so that the stop disk 85 is also rotated in the clockwise direction in order that the index pointer 98 may b rotated into any desired co-- operation with the time ring 16 thus setting the stop clock time. After thus setting the stop.

clock time, the start clock time is set by rotating the setting knob ill! in the clockwise direction so as to efiect rotation of the start gear 81 in the counterclockwise direction. Counterclockwise rotation of the start gear 31 effects corresponding rotation of the start disk 85 so that the lug disengages the adjacent end of the slot 96 formed in the stop disk 35, whereby the stop disk 85 is left in its set position and the start disk 86 is moved in the counterclockwise direction thereunder so that the stop disk 85 is now out of its normal position and the ends of the red band 99 and the scale 168 are exposed through the adjacent end of the slot 96. More particularly, the start disk 85 is thus rotated in the counterclockwise direction until there is exposed in the adjacent end of the slot 96 the required portions of the red band 93 and the scale Hi0, setting the start clock time and indicating the clock time interval between the set stop clock time and the set start clock time. At this time, both the start disk 86 and the stop disk 85 are at rest respectively indicating the set start clock time and the set stop clock time.

As time proceeds and at the set start clock time, the hour arbor E5 is again rotated into coincidence with the start disk 86, whereby the start disk 33 again occupies its normal position; and at this time, the arm 93 engages the lug $34 so that the hour arbor 65 picks-up the start gear 81 and the start disk 85 for further rotation therewith. This pick-up of the start disk 86 at the set start clock time efiects a switching control, a explained more fully hereinafter. Now as time proceeds, the start disk 85 is rotated toward the stop disk 85 so that at the set stop clock time, the start disk 85 is again rotated into coincidence with the stop disk 85, whereby the lug 95 again engages the adjacent end of the slot 96 provided in the stop disk 85 in its normal position effecting pick-up of the stop disk 35 and further rotation thereof. This pick-up of the stop disk 85 at the set stop clock time effects a switching control, as explained more fully hereinafter. At this time, both the start disk as and the stop disk 85 occupy their normal positions, whereby they are both rotated in the clockwise direction with the hour arbor 65, in the manner previously explained.

Considering now the interconnection between the clock mechanism and the oven selector switch 32, it is noted that the stop disk 85 and the start disk 86 in fact comprise gears being respectively provided about the peripheries thereof with the teeth respectively indicated at m6 and 19?. A first pinion I68 rotatably mounted on the front end of a shaft Hie carried by the plates 55 and 5? is arranged in meshing relation with the teeth m8 on the stop disk 85 so that the pinion i238 is rotated in the counterclockwise direction when the stop disk 85 is normally rotated in the clockwise direction. Similarly, a second pinion ii rotatably mounted on the front end of a shaft Hi carried by the plates 5'6 and 51 is arranged in meshing relation with the teeth it! on the start disk 86 so that the pinion Iii? is rotated in the counterclockwise direction when the start disk 3% is normally rotated in the clockwise direction. Ratchet wheels H2 and H3 are respectively rigidly secured to the pinio ns m8 and Hi! and rotatable therewith, and

are arranged in coplaner relationship, in cooperative relation with a common pawl ll i provided on the outer end of an element H5, the

inner eedcfwhich is onne ted by a pin I IE to the u rn l f ant-arm l t at s ot t b y anddoosely Journaled o the operat n ha 33 of the ovenselector switch; 32.,

As illustrated in Fig. l, the; arm I l? (and consequently the element H) is provided with an intermediate position, shown in; full lines, and corresponding to the timer bake position of the oven selector switch Also the arm It? is provided with a normal position shown indotted lines, and to the left of; theintermediateposition thereof, and corresponding to the. normal of? position of the oven; selector switch 32; as well as a final position, shown in dotted lines, to the rig-ht of the intermediate position thereof, and. corresponding to the timer off position or e ovenselector switch- S2. The arm 51.? is the counterclockwise direction into its normal position by an arrangement including a coil spring lie surrounding theoperating shaft 33 and extending between a projection HQ carried by the front of the plate 55'and a slot I26 provided in the right-hand side of the-arm ill; The normal position of the arm I I? is established by an. associated forwardly extending stop 5 2i carried: by

the front of the plate 56; and the final position of the arm HT is established by an associated forwardlyextending stop I22 carried by the-front of'the plate 56. Thus it will be understood that the arm II? is rotatable in the clockwise directionirom, its normal position established by the stop i'ZI through its intermediate position into its final position established. by the stop against the bias of the spring H8; and of course, the

element IE5 is movable with the arm H7 as a consequence of the connection therebetween, including the pin N5, the element Ii'5- having a notch :23 formed in the loweredge thereof so as to prevent interference with the stop IZI when the arm H! occupies its final-position. Finally,

a collar I24 is rigidly secured to the operating shaft 33 rearwardly ofthe arm H1 and provided with a forwardly proiecting tabor lug I25 bent out of the body thereof and cooperating with the left-hand side of the arm III. Thus, it will be understood that when the operating shaft 33 is rotated in the clockwise direction from its normal off position, the collar i ld carried thereby causes the lug I 25- to engage the left-hand side of the arm I I! rotating the arm I I! in the clockwise direction therewith, fora purposemore fully explained hereinafter.

The element H5 is biased downwardly by an arrangement including a-coil spring I25 extendingbetween a hole- I2! formed in the intermediateportion of the element LIE and a cooperating forwardly projecting pin I28 carried by the front side of the plate 56. When. the arm I ll occupies its. normal po ition, the, element U5 is projected upwardly and to the left so that the pawl H4 is disposed well above the ratchet wheel H2 and so that a lower forwardly disposed guide portion I29 of the element I I5 rides up upon a forwardly projecting guide pin i313 carried by the front of the plate 56. When the arm 4 I! occupies its in termediate. position, the element I iii is pro ected upwardly and to the. left so that the pawl H directly engages and is latched upon the ratchet wheel H2. When the arm I. l! occupies its final position, the element H5 is projected upwardly and to the left so that the pawl I M directly engages and is latched upon the ratchet wheel l 53. Further, a forwardly projecting stop pin I3! is carried by the front of the plate and arranged toengagetheelement I-I Syhemthearm: H31 occupi s its: finalw osit on so. a to; prev nt; th paw IIA- from falling, below and out of cooperating relation with espect to the ratchet wheel H6. Finally a radially projecting pin I32v iscarr-ied by the collar I24 and arranged in cooperating relation with the stop, I22 to prevent rotation of the operating shaft 33: in, thecounterclockwise direction beyond the broil position-of the oven selector switch 32;

In View of the foregoing, it will: be understood that the ratchet wheel I :13 and the cooperating pawl H4; comprise a first latch mechanism that is set when rotation of the start disk 86is arrested to stop rotation of the ratchet wheel I I-3. Similarly the ratchet wheel I I2'and thecooperating pawl I I4 comprise asecond latchmechanismthat is set when rotation of'the stop disk is arrested to stoprotationof theratchet wheel 2-. After setting of the first and second latch mechanisms, the oven selector switch 32 is-set from its normal off position into its timerofi' positon, whereby the arm I-I'I is-rotated from its normal position through its intermediate position into its, final position against the; biasof' the spring llfl-sothat the pawl I Mengages and is latched upon the stationary ratchetwheel- I=I 3. Subsequently when rotation of the start disk 86 is initiated; the ratchet wheel I I3 is rotatedslightly irrthe counterclockwise direction so that the pawl I M disengages the teeth thereoncausjng the guide portion are of the element 511 0 ride eye; the ratchet wheel I l3 so that the pawl I.I 4 is moved into. engagement andin latched relation with the iatQhet wheel H2, the arm [I] be ngv ifiturned from its final position back into itsini crmediate position by t s in 8 ill subsequ t y hen, ro ation of the sto disk 85 is. initiated, the ratchet wheel. II 2- is rotated slightly in the counterclockwise direction so thatthe pawl H4 disengagesthe teeth thereon cau ing the guide portion L29 of the element H5, to ride over the ratchet wheel I12 so that the guide portion I 29 thereof ridesupon the pin lsumovingthe element 1 l15 fr om. engagement with the ratchet wheel N2, the a m in being returned from. its intermediate position back into its normal position, by the spring H 8.

Consideringnow the overall operation. or the timer apparatus III toicontrol an automatic cooking operation in theoven l8; the manually: onerable setting knob H] I is manipulated in; the manner previously explained so as to, effect setting of the stop, disk 85. into a desired stop: clock time and to effect setting of the start disk-86- into a desired start clock time, the disks 85, and 85 being sequentially set out of their normal positions so as to effect arresting of the rotationof the ratchet wheels H2 and. H3 and the consequent setting of the fi rst and second latch, mechanisms in themanner previously explained. The manually operable, switch knob 3,4 is then rotated in the clockwise direction to operate the oven selector switch 312 fl'Q ll its normal on position through its timer bake? position into its timer oft position so that the collar [24 mo es t e rmv Hi om. ts no ma po ition through its intermediate position into its final position against the bias ofthe spring 8;; whereby the arm I I I is restrained in-its final position bythe ratchet wheel N3 of the first latch mechanism in its set position.

Thereafter and at the set start clock time, rotation of the start disk- 86 is again initiated; whereby the slight rotation of the ratchet wheel I I3 in the counterclockwise direction releases the 11 first latch mechanism so that the pawl H4 is moved into latched relation with respect to the ratchet wheel II2 of the second latch mechanism, in order that the arm III is moved from its final position back into its intermediate position by the spring IIS. This movement of the arm I I! from its final position back into its intermediate position operates the oven selector switch 32 from its timer ofi position into its timer on position by virtue of the cooperation between the arm I I? and the lug I25 carried by the collar I24. Thereafter and at the set stop clock time, rotation of the stop disk 85 is again initiated; where= by the slight rotation of the ratchet wheel I I2 in the counterclockwise direction releases the second latch mechanism in order that the arm I I! is moved from its intermediate position back into its normal position by the spring I I8. This move ment of the arm II'I from its intermediate position back into its normal position operates the oven selector switch 32 from its timer bake position into its normal off position by virtue of the cooperation between the arm Ill and the lug I25 carried by the collar I24.

At this time the automatic cooking operation in the oven I8 is concluded and since the oven selector switch 32 occupies its normal off position, a subsequent manual control of a cooking operation in the oven I8 may be initiated merely by operating the oven selector switch 32 into the 7 required control position employing the manual knob 34 and without reference to the prior automatic cooking operation that was carried out by the timer apparatus II, as described above. Moreover at the conclusion of the automatic cooking operation, the start disk 86 and the stop disk 85 are continuously rotated with the hour arbor 65 so that the previously set start and stop clock times have been completely wiped out or erased from the timer apparatus II. The two last-mentioned features of the timer apparatus I I are very advantageous in view of the fact that no manipulation of the timer apparatus I I is required to condition the oven selector switch 32 for subsequent manual operation and since the erasure of the previously used start and stop clock times prevents any possibility of confusion the next time the operator wishes to carry out another automatic cooking operation in the oven I 8 employing different start and stop clock times.

Recapitulating, it will be appreciated that the connection between the arm III and the collar I24 is a one-way drive connection, whereby the operator at any time may manipulate the manual knob 34 in order appropriately and correspondingly to set the oven selector switch 32 and regardless of the set or unset position of the timer apparatus II. This arrangement is very advantageous as the operator at any time, even after setting the timer apparatus II, may decide to carry-out a normal bake operation or a broil operation in the oven I8 and may accordingly appropriately manipulate the manual knob 34 to bring about the required setting of the oven selector switch 32. In this case, the previously set timer apparatus I I operates through its timed controls, in the manner described, but without effect, since the arm I I1 loosely mounted upon the operating shaft 33 in its movements does not engage the lug I25 as the lug I25 carried by the collar I2 2 occupies a position to the left beyond the movements of the arm III, as illustrated in Fig. 4. In other words, when the selector switch 32 occupies either its normal bake position or its broil position, the lug I 25 occupies a position to the left beyond the limit of cooperation with the arm III, as established by the stop pin I2I, so that movements of the arm I2I under the control of the timer apparatus II are without effect.

Also, it will be understood that in the event the operator should wish immediately to initiate a cooking operation but desires the timer apparatus II to arrest the cooking operation subsequently, this may be accomplished in a ready manner merely by manipulating the settin control knob IIII to establish a stop clock time followed by operation of the manual knob 34 to move the oven selector switch 32 into its timer bake position. In this case, the cooking operation in the oven I3 proceeds immediately, and subsequently at the set stop clock time, rotation of the stop disk is initiated to bring about the release of the ratchet wheel II2 of the second latch mechanism so that the arm II? is moved from its intermediate position back into its normal position effecting operation of the oven selector switch 32 from its timer bake position into its normal off position.

Further, it is pointed out that the wipe-out arrangement of the set start and stop clock times following the automatic operation is further advantageous in that it renders the timer apparatus II under normal conditions more nearly similar to an ordinary kitchen clock without the presentation of the various times that might have been employed in conjunction with a prior auto-- matic cooking operation. This causes the timer apparatus II to be simple and very attractive as a kitchen clock. Moreover, the arrangement of the manual control knob 34 of the oven selector switch 32 closely adjacent to the manually operable timer setting knob IIJI is very advantageous as it facilitates sequential operation of these two manually operable control knobs and serves to remind the operator that these two control knobs must be sequentially manipulated in order to bring about an automatic cooking operation in the oven I8. In other words, the complete removal of the manual control knob 34 of the oven selector switch 32 from the remainder of the manual control knobs 23, etc., upon the backsplash 22 and the close association of the manual control knob 34 with the manual control knob IEBI reduce the errors of the operator and greatly facilitate control of cooking operations in the oven I8.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In combination, a control switch having an ofi position and a normal on position and a timer on position, a movable element having a normal position and an operated position, a single manually operable member for selectively operating said switch into any one of its positions independently of the position of said element and at the will of the operator, a spring biasing said element into its normal position, means responsive to operation of said switch from its on position into its timer on position for moving said element against the bias of said spring from its normal position into its operated position, latch mechanism for restraining said element in its operated position, said spring returning said element from its operated position back into its normal position in response to the release of said latch mechas eaves nism, means responsive to movement or saidelement, from its operatedposition back into itsnorma l position for operating said switch into its off position only in the event said switch oocupies its timer on position, clock mechanism, indicator mechanism controlled by said clock mechanism for releasing said latch mechanism at a set clock time, and manually operable means for selectively setting said indicator mechanism to .any desired clock time.

2. The combination set forth in claim 1, wherein said switch is-of the rotary snap type, saidnormal on position and said timer on position are respectively disposed on opposite sides of said. off position, and said manually operable member is in the form of a rotatable knob.

3. In combination, acontrolswitch having an off position and a normal on position and a timer on position, a movable element having a normal position and an operated position, a single man.- ually operable member for selectively operating said switch into any one of its positions independently of the position of said element and at the will of the operatona spring biasing said element into its normal position, means responsive to operation of said switch from its off position into its timer on position for moving said element against the biasof said spring from its normal position into its operated position, latch mechanism cooperating with said element and having a set position and a release position, said latch mechanism in its set position restraining said element .in its operated position, said spring returning said element from its operated position back into its normal position in response to operation of said latch mechanism into its release position, means responsive to movement of said element from its operated position back into its normal position for operating said switch into its off position only in the event. said switch occupies its timer on position, clock mechanism, indicator mechanism controlled by said clock mechanism and having a normal position and a variable set position, manually operable means for selectively moving said indicator mechanism from position.

4. In combination, a control switch having a normalofi position and a timer ofi position anda normal on position and a timer on position, a movable element having a normal position and an intermediate position and a final position, a single manually operable member for selectively operat ing said switch into any one of its positions independently of the position ofsaid element and at the willof the operator, a spring biasing said element. into its normal position, means responsive to operation of said switch from its normal off position into its timer oh position for moving said element against the bias of said spring from its normal position through its intermediate position into its final position, first latch mechanism for restraining said element in its final position, second latch mechanism forrestraining said element in itsintermediate. position, said-spring returning said from its final position backinto itsintcmediatanosition in response. to thereleaseof said first, latch mechanism and re.- tu-rning said element-1mm its intermediate position back intoits normal position in response to the release of said second latch mechanism, meansresponsiveto movement of said element .fromits fmal position back into its intermediate position for operating said. switch .into its timer on position only in the event said switch occupies its timer 'ofi position and responsive to-movement at said elementzirom its intermediate position backlinto its normal position for operating said switch into its normal off position only in the event said switch occupies its timer on position, clock mechanism, first indicator mechanism controlled by said. clock mechanism. for releasing said first latch mechanism at a set start clock second. indicator mechanism controlled by said clock mechanism for releasing said second latch mechanism at a set stop clock time, and manually operable means for selectively setting said first indicator mechanism to any desired start clock time and for selectively setting said second indicator mechanism to any desired stop clock time.

5. Thecombination set forth in claim4, whereinsaidswitch is of the rotary'snap type, said normal ofi position is disposed intermediate said normal on positionand said timer on position, said timer on position is disposed intermediate said normal off position and said timer off position, and. said manually operable member is inthe form of a rotatable knob.

6. In combination, a control switch having a normal off position and a timer off position and a normal on position and a timer on position, a movable-element having a normal position and an intermediate position and a. final position, a single manually operable member for selectively operating said switch into any one of its positions independently of the position of said element and at the will of the operatona spring biasing said element into its normal position, means responiv t operation of said switch from its normal mechanism .in its set position restraining said element in its intermediate position when it is moved thereinto, said springreturning said element from its final position back into its intermediate position in response to operation of said first latch mechanisminto its release position and returning said element from its intermediate position back into its normal position in response to operation ofsaid second latch mechanism into its release position, means responsive to movement of said elementfrom its final position .backintoits intermediate position for operating said switch into itstimer onposition only in the event said switch occupies its timer oil ,position and responsive to movement of said element .from its intermediate position back into its normal position for operating said switch into its normal ofi position only in the event said switch occupies its timer on position, clock mechanism, first indicator mechanism controlled by said clock mechanism and having a normal position and a variable set position, second indicator mechanism controlled by said clock mechanism and having a normal position and a variable set position, manually operable means for selectively moving said first indicator mechanism from its normal position into its set position corresponding to any desired start clock time and for selectively moving said second indicator mechanism from its normal position into its set position corresponding to any desired stop clock time, means including said clock mechanism for returning said first indicator mechanism from its set position back into its normal position at said set start clock time and for returning said second indicator mechanism from its set position back into its normal position at said set stop clock time, means responsive to movement of said first indicator mechanism out of its normal position'for operating said first latch mechanism into its set position and responsive to movement of said first indicator mechanism back into its normal position for operating said first latch mechanism into its release position, and means responsive to movement of said second indicator mechanism out of its normal position for operating said second latch mechanism into its set position and responsive to movement of said second indicator mechanism back into its normal position for operat-Eng said second latch mechanism into its release position.

7. In combination, clock mechanism including a rotatable time arbor, a rotatably mounted start disk having a normal position coincident with said arbor and a variable set position disposed ahead of said arbor, said start disk being rotated by said arbor only when said start disk is in its normal position, a rotatably mounted stop disk having a normal position coincident with said start disk and a variable set position disposed ahead of said start disk, said stop disk being rotated by said start disk only when said stop disk is in its normal position, manually operable means for selectively setting said start disk out of its normal position into its set position corresponding to any desired start clock time and for selectively setting said stop disk out of its normal position into its set position corresponding to any desired stop clock time, a device having a plurality of control positions, means responsive to subsequent rotation of said arbor into coincidence with said start disk at said set start clock time for operating said device into a first of its control positions, and means responsive to subsequent rotation of said start disk into coincidence with said stop disk at said set stop clock time for operating said device into a second of its control positions.

8. In combination, clock mechanism including a rotatable time arbor, a rotatably mounted start disk having a normal position coincident with said arbor and a variable set position disposed ahead of said arbor, said start disk being rotated by said arbor only when said start disk is in its normal position, a rotatably mounted stop disk having a normal position coincident with said start disk and a variable set position disposed ahead or" said start disk, said stop disk being ro tated by said start disk only when said stop disk is in its normal position, manually operable means for selectively setting said start disk out of its normal position into its set position corresponding to any desired start clock time and for selectively setting said stop disk out of its normal position into its set position corresponding to any' desired stop clock time, a control switch having a first oii position and a second off position and an on position, manually operable means for operating said switch from its first off position into its second on position, means responsive to subsequent rotation of said arbor into coincidence with said start disk at set start time for operating said switch from its second of" position into its on position, and means responsive to subsequent rotation of said start disk into coincidence with said stop disk at said set stop clock time for operating said device from its on position back into its first on? position.

9. In combination, clock mechanism including a rotatable time arbor, a rotatably mounted start disk having a normal position coincident with said arbor and a variable set position disposed ahead of said arbor, said start disk being rotated by said arbor only when said start disk is in its normal position, a rotatably mounted stop disk having a normal position coincident with said start disk and a variable set position disposed ahead of said start disk, said stop disk being rotated by said start disk only when said step disk is in its normal position, manually operable means for selectively setting said start disk out or its normal position into its set position corresponding to any desired start clock time and for selectively setting said stop disk out of its normal position into its set position corresponding to any desired stop clock time, said stop disk being disposed in covering relation with said start disk and having a cut-out therein cooperating with a time index provided on said start disk, a portion of said time index being exposed through said cut-out only when said start disk is out of coincidence with said stop disk, the initial exposed portion of said index when both said start disk and said stop disk occupy their set positions corresponding to the total clock time interval between said start clock time and said stop clock time and the subsequent exposed portion of said index when said start disk occupies its normal position and said stop disk occupies its set position corresponding to the unelapsed portion of said total clock time interval, a device having a plurality of control positions, means responsive to subsequent rotation of said arbor into coincidence with said start disk at said set start clock time for operating said device into a first of its control positions, and means responsive to subsequent rotation of said start disk into coincidence with said stop disk at said set stop clock time for operating said device into a second of its control positions, i

10. The combination set forth in claim 9, and further comprising a stationary clock index cooperating with said stop disk and indicating said stop clock time when said stop disk occupies its set position.

11. In combination, clock mechanism including a rotatable time arbor, a rotatably mounted start disk having a normal position coin ident with said arbor and a variable set position disposed ahead of said arbor, start disk being rotated by said arbor only when said start disk is in its normal position, a rotatably mounted stop disk having a normal position ccicident with said start disk and a variable set position disposed ahead of said start disk, said step disk being rotated by said start disk only when said stop disk is in its normal position, a single manually operable member for selectively rotating said start disk in either direction, rotation of said start disk in the" clockwise direction rotatingsa-idstart disk out of its: normal position and causing said start disk to rotate said stop disk therewith to accommodate rotation of stop disk into any desired set position, subsequent rotation of said start disk in the counterclockwise direction being independent of said stop disk so as to leave said stop disk out of its normal position and to accommodate rotation of said start disk into any desired set position, a device having a plurality of control positions, means responsive to subsequent rotation of said armor into coincidence with said start disk at said set start clock time for operating said device into a first of its control positions, and means responsive to subsequent rotation of said start disk into coincidence with said stop disk at said set stop clock time for operating said device with a secend of its control positions.

12. In combination, clock mechanism including a rotatable time arbor, a rotatabl-y mounted start disk having a normal position coincident with said arbor and a variable set position disposed ahead of said arbor, said start disk being rotated by said arbor only when said start disk is in its normal position, a rotatably mounted stop disk having a normal position coincident with said start disk and a variable set position disposed ahead of said start disk, said stop disk being rotated by said start disk only when said stop disk is in its normal position, manually operable means for selectively setting said start disk out of its normal position into its set position corresponding to any desired start clock time "and for selectively setting said stop disk out of its normal position into its set position corresponding to any desired stop clock time, said arbor picking-up said start disk and again rotating it therewith when said arbor is rotated into coincidence therewith at said set start clock time, said start disk picking-up said stop disk and again rotating it therewith when said start disk is rotated into coincidence therewith at said set stop clock time, a device having a plurality of control positions, means responsive to rotation of said start disk following arresting of rotation thereof for operating said device into a first of its control positions, and means responsive to rotation of said stop disk following arresting of rotation thereof for operating said device into a second of its control positions. I

13. In combination, clock mechanism including a rotatable time arbon-a rotatably mounted start disk having a normal position coincident with said arbor and a-variable set position disposed ahead of said arbor, said start disk being rotated by said arbor only when said start disk is in its normal position, a rotatably mounted stop disk having a normal position coincident with said start disk and a variable set position disposed ahead of said start disk, said stop disk being rotated by said start disk only when said stop disk is in its normal position, manually operable means for selectively setting said start disk out of its normal position into its set position corresponding to any desired start clock. time and for selectively setting said stop disk out of its normal position into its set position corresponding to any desired stop clock time, said arbor picking-up said start and again rotating it therewith whensaid arbor is rotated into coincidence therewith at said set start clock time, said start disk picking-up said stop disk and again rotating it therewith when said start disk is rotated into coincidence therewith at said set stop clock; time, firstletch, mechanism cooperating with said start disk andset; in r sponse to arresting of; rotation thereof; and released in sponse to continued. rotation, thereof, second: latch mechanism cooperating with said step disk and set in response to arresting of rotation thereof and released in response to continued rotation thereof, a control device. having first and second and third positions, means governed when said first latch mechanism is set for restrainingsaid control device in its first position, means, re.- sponsive to the release of said first latch mechanism for moving said control device from its first position into its second position, means governed when said second latch mechanism is set for restraining said control device in its second position, and means responsive to the release oi! said second latch mechanism for moving said control device from its second position into its third position.

14. The combination set forth in claim 13, wherein said first latch mechanism includes a first ratchet member driven by said start disk, said second latch mechanism includes a second ratchet member driven by said stop disk, andsaid first and second latch mechanisms include a common pawl member "successively cooperating with said first and second ratchet members.

15-. In combination, clock mechanism including a rotatable time arbor, a rotatably mounted start disk having a normal position coincident with said arbor and a variable set position disposed ahead of said arbor, said start disk being rotated by said arbor only when said start disk is F in its normal position, a rotatably mounted stop disk having a normal position coincident with said start disk and a variable set position dispc-sed ahead of said start disk, said stop disk being rotated by said start disk only when said stop disk is in its normal position, manually operable means for selectively setting said start disk out of its normal position into its set position corresponding to any desired start clock time and ior selectively setting said stop disk but of its normal position into its set position correspond ing to any desired stop clock time, said'arbor picking-up said start disk and again rotating it therewith when said arbor is rotated in coincidence therewith at said set start clock time, said start disk picking-up said stop disk and again rotating it therewith when said start disk is totated into coincidence therewith at said set stop clock time, said start disk having teeth thereon, a first pinion meshing with the teeth on said start disk, said stop disk having teeth thereon, a second pinion meshing with the teeth on said stop disk, a device having a plurality of control positions, and means successively controlled by said first and second pinions for successively operating said device between different ones of its control positions.

16. In combination, clock mechanism including concentric rotatable minute an hour arbors respectively carrying minute and hour hands, a surroundin r ns co perating with said minute and hour hands and provided with a cooperattime index, a rear start disk mounted for rotation concentric with said hour arbor within said ring and having a normal position coincident with said hour arbor and a variable set position disposed ahead of said hour arbor, a drive connection between said hour arbor and said start disk that is engaged only when said start disk occupies its normal position, whereby said start disk is rotated with said hour arbor only when it occupies its normal position, a front stop disk mounted for rotation concentric with said hour arbor within said ring and having a normal position coincident with said start disk and a variable set position disposed ahead of said start disk, a drive connection between said start disk and said stop disk that is engaged only when said stop disk occupies its normal position, whereby said stop disk is rotated with said start disk only when it occupies its normal position, manually operable means for selectively setting said start disk out of its normal position into its set position corresponding to any desired start clock time and for selectively setting said stop disk out of its normal position into its set position corresponding to any desired stop clock time, the set position of said start disk with respect to said ring indicating said set start clock time and the set position of said stop disk with respect to said ring indicating said set stop clock time and the relative positions of said disks with respect to each other indicating the clock time interval between said start clock time and said stop clock time, and a device operated into a first position under the control of said start disk at said start clock time and operated into a second position under the control of said stop disk at said stop clock time.

17. The combination set forth in claim 16, wherein said stop disk is provided with a cutout therein and said start disk is provided with a cooperating scale that is exposed though said cut-out only when said stop disk is out of its normal position, rotation of said start disk with said hour arbor when it occupies its normal position gradually removing said scale from its exposed position through said cut-out until finally said scale is concealed by said stop disk when said stop disk occupies its normal position, the exposed position of said scale indicating the unelapsed portion of said clock time interval.

18. In combination, clock mechanism including concentric rotatable minute and hour arbors respectively carrying minute and hour hands, a surrounding ring cooperating with said minute and hour hands and provided with a cooperating time index, a rear start disk mounted for rotation concentric with said hour arbor within said ring and having a normal position coincident with said hour arbor and a variable set position disposed ahead of said hour arbor, a drive connection between said hour arbor and said start disk that is engaged only when said stark disk occupies its normal position, whereby said start disk is rotated with said hour arbor only when it occupies its normal position, a front stop disk mounted for rotation concentric with said hour arbor within said ring and having a normal position coincident with said start disk and a variable set position disposed ahead of said start disk, 8, drive connection between said start disk and said stop disk that is engaged only when said stop disk occupies its normal position, whereby said stop disk is rotated with said start disk only when it occupies its normal position, manually operable means for rotating said start disk in either direction, whereby rotation of said start disk in the clockwise direction rotates said start disk out of its normal position and rotates said stop disk therewith and moves said stop disk into any desired set position and subsequent rotation of said start disk in the counterclockwise direction is independent of said stop disk and leaves said stop disk out of its normal position and moves said start disk into any desired set position, the set position of said start disk with respect to said ring indicating said set start clock time and the set position of said stop disk with respect to said ring indicating said set stop clock time and the relative positions of said disks with respect to each other indicating the clock time interval between said start clock time and said stop clock time, and a device operated into a first position under the control of said start disk at said start clock time and operated into a second position under the control of said stop disk at said stop clock time.

19. The combination set forth in claim 18, wherein said manually operable means includes a knob carried by a rotatably mounted shaft, a pinion carried by said shaft, and a gear carried by said start disk and meshing with said pinion.

20. The combination set forth in claim 15, wherein said minute arbor is in the form of a centrally disposed shaft, said hour arbor is in the form of a sleeve surrounding said shaft, and said start disk and said stop disk are both mounted and supported upon said sleeve and rotatable independently thereof.

21. In an electric heating system including an oven provided with electric heating units, and an oven control switch having an off position and a broil position and a normal bake position and a timer bake position, said switch in its on position deenergizing said heating units, said switch in its broil position selectively energizing said heating units to establish a broiling condition in said oven, said switch in either its normal bake position or its timer bake position selectively energizing said heating units to establish a baking condition in said oven; the combination comprising a movable element having a normal position and an operated position, a single manually operable member for selectively operating said switch into any one of its positions independently of the position of said element and at the will of the operator, a spring biasing said element into its normal position, means responsive to operation of said switch from its off position into its timer bake position for moving said element against the bias of said spring from its normal position into its operated position, l'atch mechanism for restraining said element in its operated position, said spring returning said element from its operated position back into its normal position in response to the release of said latch mechanism, means responsive to movement of said element from its operated position back into its normal position for operating said switch into its ofi position only in the event said switch occupies its timer bake position, clock mechanism, indicator mechanism controlled by said clock mechanism for releasing said latch mechanism at a set clock time, and manually operable means for selectively setting said indicator mechanism to any desired clock time.

22. In an electric heating system including an oven provided with electric heating units, an oven control switch having a normal oii position and a timer off position and a broil position and a normal bake position and timer bake position, said switch in either its normal off position or its timer ofi position deenergizing said heating units, said switch in its broil position selectively energizing said heating units to establish a broiling condition in said oven, said switch in either its normal bake position or its timer bake position selectively energizing said heating units to establish a baking condition in said oven; the combination comprising a movable element having a normal position and an intermediate posi- 21 tion and a final position, a single manually operable member for selectively operating said switch into any one of its positions independently of the position of said element and at the will of the operator, a spring biasing said element into its normal position, means responsive to operation of said switch from its normal off position into its timer off position for moving said element against the bias of said spring from its normal position through its intermediate position into its final position, first latch mechanism for restraining said element in its final position, second latch mechanism for restraining said element in its intermediate position, said spring returning said element from its final position back into its intermediate position in response to the release of said first latch mechanism and returning said element from its intermediate position back into its normal position in response to the release of said second latch mechanism, means responsive to movement of said element from its final position back into its intermediate position for operating said switch into its timer bake position only in the event said switch occupies its timer off position and responsive to movement of said 22 element from its intermediate position back into its normal position for operating said switch into its normal off position only in the event said switch occupies its timer bake position, clock mechanism, first indicator mechanism controlled by said clock mechanism for releasing said first latch mechanism at a set start clock time, second indicator mechanism controlled by said clock mechanism for releasing said second latch mechanism at a set stop clock time, and manually operable means for selectively setting said first indicator mechanism to any desired start clock time and for selectively setting said second indicator mechanism to any desired stop clock time.

DOUGLAS F. ILLIAN. NORMAN T. TERP.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,758,619 Phillip May 13, 1930 2,200,110 Andersen May '7, 1940 2,638,979 Harris May 19, 1953 

